My 1991 350 SDL has a serpentine belt drive system with a dual shock absorber system to take up slack and keep tension on the belt. The previous owner replaced one (maybe both) of these shocks about once every 1.5 years. Is this normal? Is there an alternative to using a part with such a short useful life?

I keep wondering if I am missing something.

Thanks to everyone. Appreciate a response to the bb as well as to my email.